To provide a wheel bearing device capable of preventing looseness accompanying with torque transmission of a nut giving fastening axial force to a hub wheel by being screwed with a stem part of an outer ring of a constant velocity joint.

The wheel bearing device is provided with: an outer member 1; an inner member 2; a rolling element 5 interposed between opposed double-row rolling surfaces 3, 4 of both members; and the outer ring 63 of the constant velocity joint. The inner member 2 makes the hub wheel 9 having a through-hole 11 at a center as a constitution part, and a stem part 63a of the outer ring 63 of the constant velocity joint is spline-fitted to the through-hole 11. The inner member 2 is fastened by the nut 64 pressed to a side end surface 9d of an out-board of the hub wheel while screwed with an end of an out-board side of the stem part and a shoulder part 63b of a base end of the stem part abutted on a side end surface of an in-board of the inner member. An axial position relative to a side end surface 9d of the out-board of the hub wheel of a side end of the out-board of a stem part male spline 63aa is set so that relative displacement is not generated between the nut 64 and the side end surface 9d of the out-board of the hub wheel.